package com.yiruantong.common.encrypt.filter;

import cn.hutool.core.io.IoUtil;
import jakarta.servlet.ReadListener;
import jakarta.servlet.ServletInputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletRequestWrapper;
import com.yiruantong.common.core.constant.Constants;
import com.yiruantong.common.encrypt.utils.EncryptUtils;
import org.springframework.http.MediaType;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

/**
 * 解密请求参数工具类
 *
 * @author wdhcr
 */
public class DecryptRequestBodyWrapper extends HttpServletRequestWrapper {

  private final byte[] body;

  public DecryptRequestBodyWrapper(HttpServletRequest request, String publicKey, String privateKey, String headerFlag) throws IOException {
    super(request);
    // 获取 AES 密码 采用 RSA 加密
    String headerRsa = request.getHeader(headerFlag);
    String decryptAes = EncryptUtils.decryptByRsa(headerRsa, privateKey);
    // 解密 AES 密码
    String aesPassword = EncryptUtils.decryptByBase64(decryptAes);
    request.setCharacterEncoding(Constants.UTF8);
    byte[] readBytes = IoUtil.readBytes(request.getInputStream(), false);
    String requestBody = new String(readBytes, StandardCharsets.UTF_8);
    // 解密 body 采用 AES 加密
    String decryptBody = EncryptUtils.decryptByAes(requestBody, aesPassword);
    body = decryptBody.getBytes(StandardCharsets.UTF_8);
  }

  @Override
  public BufferedReader getReader() {
    return new BufferedReader(new InputStreamReader(getInputStream()));
  }


  @Override
  public int getContentLength() {
    return body.length;
  }

  @Override
  public long getContentLengthLong() {
    return body.length;
  }

  @Override
  public String getContentType() {
    return MediaType.APPLICATION_JSON_VALUE;
  }


  @Override
  public ServletInputStream getInputStream() {
    final ByteArrayInputStream bais = new ByteArrayInputStream(body);
    return new ServletInputStream() {
      @Override
      public int read() {
        return bais.read();
      }

      @Override
      public int available() {
        return body.length;
      }

      @Override
      public boolean isFinished() {
        return false;
      }

      @Override
      public boolean isReady() {
        return false;
      }

      @Override
      public void setReadListener(ReadListener readListener) {

      }
    };
  }
}
